Advocates of plastics made from soybeans or other plant materials like to tout their wares as having an environmentally friendly footprint, where raw materials are replenished as quickly as the next growing season in a cycle they dub ``birth to reincarnation.''
The big challenge for the industry, though, seems to be getting out of the delivery room.
How to see biobased polymers mature beyond infancy was the talk among the engineers, consultants and academics at the Society of Plastics Engineers' Global Plastics Environmental Conference, held Feb. 18-19 in Detroit. The event was abuzz with positive predictions for bioplastics, tempered with the reality of the marketplace.
``The real issues are bringing it out from the researcher's bench to the real world,'' said John Cerny, staff engineer for biobased polymers with John Deere Inc.'s technology center in Moline, Ill.
Deere is using a thermoset resin that is 25 percent renewable, from soy and corn, in hood and body panels in its combines, and plans to expand that to other products, Cerny said. Case LLC is also using soy-based resin in a combine, part of a market development push by agricultural equipment manufacturers.
Other companies, like Sony Corp. and Ford Motor Co., have dabbled in vegetable-based plastics.
But basic questions need to be answered before large manufacturers like car companies will be comfortable using plant-based polymers, said Phil Sarnacke, an industry consultant with OmniTech International, Ltd., in Midland, Mich. OmniTech works for the United Soybean Board.
Sarnacke and David Reed from General Motors Corp., delivered a paper to the conference that recommended that auto makers launch a cooperative precompetitive research program to evaluate biobased polymers, and create a database of cost, performance and environmental issues for engineers to reference.
``The auto [industry's] lack of use of biomass products is in part due to a lack of thorough, critical evaluation of the biomass products and their potential,'' they wrote.
Those pushing biobased polymers see potential. Biobased materials are used in about 3 percent of the $280 billion U.S. market for polymers and chemicals now, but some estimates say that will grow to 20 percent by 2010, said Margaret Baumann, president of consulting firm G.H. Associates in Lebanon, N.J.
Biopolymers could offer a homegrown economic advantage to the U.S. plastics industry, which has been hurt by steep price increases in natural gas, she said. The U.S. industry could regain some global competitiveness by tapping American agriculture for feedstock, and at the same time reduce the country's dependence on foreign energy sources and lessen greenhouse gas generation, Baumann said.
Biopolymers that are achieving success now, she said, are adding value, like providing a soft touch for products like drapes. Another example: Deere's Cerny said its soy-based resin parts are better because they do not need to be repainted or repaired as often.
The Deere parts made with biobased resins are cost competitive, but the company still wants prices for biobased resin to drop 10-15 percent, Cerny said.
While biopolymers were the toast of the conference - they were the single largest paper topic this year - proponents conceded that they're not always the slam-dunk environmental win that some assume.
John Dorgan, a chemistry professor at the Colorado School of Mines, said that some studies, like an August 2000 article in Scientific American magazine, have challenged the idea that bioplastics are defacto more environmentally friendly.
The report claimed that some bioplastics require more energy to produce than some traditional petrochemical-based plastics, although it did note that some bioplastics fared better than their petroleum cousins.
A study delivered at the conference compared using soy and petroleum in making polyol, a primary ingredient of polyurethane foam, and initially found that the petroleum-based version was more environmentally friendly, mainly because of the environmental harm from modern farming.
But then researchers looked at the underlying data and found incorrect assumptions about pesticide runoff and farming practices. When those were changed, soy came out looking better, said Jack Pollack, a consultant with OmniTech. The company was able to convince government researchers doing the study to correct their data, he said.
Evaluating environmental impact can be subjective, but biobased plastics still offer significant chances to reduce energy use and combat global warming, and are part of a longer-term shift toward more sustainable manufacturing practices, said Ramani Narayan, professor of chemical and biochemical engineering at Michigan State University in East Lansing, Mich.